I have a bathroom in my basement and the toilet flange that was installed down there is not installed correctly. The toilet sits higher on one side then the other. The flange is glued and screwed. The flange is sitting higher on one side then the other.

My question is, is there a fix for this like a flange that is made to go into the 3" existing flange after I cut it off or do I need to cut it off even with the floor and then remove the flange piping inside the 3" pipe.What is my best bet.